Conventionally, a general-purpose engine used in an operating machine or the like adopts a carburetor to supply a mixture of fuel and air to the engine; in order to start the engine, it is necessary to turn on an engine switch with a fuel cock opened to allow fuel supply to the engine. On the other hand, even when the fuel cock is not closed, the engine switch is simply turned off to stop the ignition, and thus the operation of the engine is stopped. Hence, it is likely that, when the engine is stopped, only the engine switch is turned off but the fuel cock is mistakenly left open. In this case, the fuel may diffuse into the air or flow into the engine.
To solve this problem, a structure for preventing a fuel cock from being mistakenly left open when an engine is stopped is proposed. For example, in a fuel cock structure disclosed in Patent Document 1, a mechanism is provided in which the turning operation of a switching lever pivoted on the main body of a fuel cock is performed, in a coordinated manner, together with the turning of a switch case with respect to an inner case; the fuel cock of a carburetor is proposed in which a contact of an engine switch is provided on each of the side of the inner case and the side of the switch case. In this conventional art, when the switching lever is turned to a stop position when the engine is stopped, a fuel passage between a fuel tank and the carburetor is closed, and the contact of the engine switch is opened, in a coordinated manner, together with the movement of the switching lever, with the result that the ignition function of the engine is stopped. In this way, the supply of fuel to the carburetor is stopped and simultaneously the ignition function of the engine is stopped.